Do you not see that keeping Pitbulls at home is what's causing the problem? They're unsocialised and unexercised and going out of their minds with pent up energy. I don't believe in killing healthy dogs either, so I disagree with your solution. The answer, as I said before, is responsible ownership. Get rid of BSL. Allow the dogs go to puppy school and dog training classes. Allow them to be walked in public and interact with society. Keeping them behind closed doors is not the answer IMO.